Nut-tapping machine



Ndv. 9, 1929.

W. A. CREHAN NUT TAPPING MACHINE Filed Dec. 1925 5 Sheets-Sheet William A. 'Crelmm bwmwmizww Nov. 19, 1929. w. A. CREHAN 1,736,581

NUT TAPFZFJG MACHINE Filed 1925 5 Sheets-Sheet 2 FIG. 2

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NUT TAPPING MACHINE Filed Dec 1925 5 Sheets-Sheet 4 FlG. E1

INVENTOR Fig. 7 WiHiam A. Crehan Patented Nov. 19, 1929 UNITED STATES WILLIAM A. CREHAN, OF PITTSBURGH, PENNSYLVANIA NUT TAPPING MACHINE Application filed December 2, 1925. Serial No. 72,726.

This invention relates to nut tapping mechanism.

The object of the invention is to provide simple and efiicient mechanism for feeding, tapping, and discharging' nuts.

in the accompanying drawings Figure 1 is a plan view of the complete nut tapping mechanism of the present invention; Figure is a side elevation of the same; Figure 3 is a front elevation of one of the tap holding chucks of the mechanism; Figure 4 is a ver tical sectional view of such chuck, showing the forward jaws open to permit the passage of a nut into the chuck; Figure 5 is a similar view, showing the rearward jaws open to permit the passage of a nut from the chuck and off the shank of the tap; Figure 6 is a detail elevation of the chuck operating means; Figure 7 is an enlarged detail plan view of a safety device to prevent jamming of the tap; Figure 8 is a detail elevation of the nut feeding device in conjunction with the nut holding matrix of the mechanism; Figure 9 is a vertical sectional view taken on the line 9--9 of Figure 8; and Figure 10 is a sectional detail view of the nut feeding matrix taken at right angles to the showing of Figure 9.

In the drawings the reference numeral 1 designates the bed plate of the machine. On

bed plate 1 are housings 3 and 4 which support two central pulley shafts 2 and 2, each of which carries two pulleys. he inner pulleys 5 and 6 on the shafts are loose thereon,

while the pulleys 7 and 8 are keyed respectively to the shaft 2 and the shaft 2*. Adjacent pulleys 7 and 8, on the shafts 2 and 2, are pinions 9 and 10 meshing with gears 11 and 12 respectively. On the same shafts,

outwardly of housings 3 and 4, are keyed helical driving gears 13 and 14.

Since the assembled machine (as shown) comprises two identical mechanisms, which are mounted on a common bed plate; from 45 this point in the specification a description of one such mechanical element, as that to I the left in the drawings and comprising the helical gear 13, "will be given as applicable to both the elements.

50 In mesh with helical gear 13 are gears 15 and 16, which are fixed to the chuck spindles 17 and 18. These spindles 17 and 18, which have the tap chucks 19 and 20 atlixed thereto,

are hollow and are inclined at suchan angle from the horizontal that the nuts can slide along the shanks of the taps 21 and 22 and out of the'hollow spindles.

Spindles 17 and 18 are slidably mounted in the standards 23 and 24 respectively. Means for reciprocating the spindles in their housings comprise the gear 11, which is keyed to a shaft 25 in housings 26 and 27. Adjacent the housing 27 is a pinion 28, which meshes with a gear 29 fixed on a cam shaft 30 mounted in standards 31 and 32. The shaft 30 carries a cylindrical member 33, having therein the cam way 33.

In the cam way 33 are rollers 34 and 35, which are mounted respectively on levers 36 and 37. These levers are respectively fitted on cross shafts 38 and 39, which are housed in bearings 40 and 41. Shafts 38 and 39 carry forked levers 42 and 43 which have a pin engagement with collars 44 and 44 which are loosely mounted on the spindles 17 and 18, and bear respectively against collars 45 and 46 fixed to the respective spindles.

As the cam cylinder 33 revolves the engage,- ment of rollers 34 and 35 in cam way 33 produces oscillation of the levers 36 and 37. These levers transmit the motion to shafts 38 anl 39, which by their oscillation move the levers 42 and 43. By the collar arrangement described immediately above, the oscillation of these levers imparts reciprocating movement to the chuck carrying spindles 17 and Each of the chucks 19 and 20 comprises an outer casing 47, having therein a recess 48 for receiving the standard 23 or 24 adjacent which the chuck is mounted. Such standard holds this casing '47 in fixed position relatively to the bed plate 1 of the machine. In the forward portion of the spindle are four slots 49 for receiving the tap holding dies 50* and four slots 49" for receiving the tap holding dies 50. The sets of dies are respectively held in place in these slots by collars 51 and 52, which are in turn secured by screws 53.

the spindle is moved forwardly by its actuating lever, the dies 50 move outwardly beyond a squared engaging portion 22 on the shank of tap 22. During this movement the tap is held to rotate with the spindle by the \mgagement of the rearward dies 50* with a souared portion :22" adjacent the rearward extremity of the tap shank.

in order that the dies may open and close to disengage or engage the proper portions of the tap shank, they are yieldingly pressed outwardly by springs 54 mounted in apertures 55 in the end portion 18 of the spindle. As the spindle moves forwardly the dies 5O slide along the inner surface of the casing 47, to which they are pressed by springs 54. Dies 50 have thereon beveled faces 50, which come in contact with a chamfered face 57 on an annular member 57", as the spindle and dies move forwardly. Thecooperation of these inclined faces permits; spreading of the forward dies 50 into the position shown in Figure 4 of the drawings, without passage of L the dies beyond the-casing 47.

Similarly the beveled portion 50 on the rearward dies 50", cooperating with a chamfered face 57 on a similar annular member 57, permits spreading of the rearward dies.

In the most forwardly position of the spindle and tap, shown in Figure 4, the tap enters a pierced nut blank 60 (see dotted line showing of Figure 9). Before the start of this forward movement, tap 22 has finished tapping nut 59; nut 58 having been tapped by the preceding movement. Of these, the nut 59 is shown in Figure 4 as just having passed over the tap 22 on to the shank 22 while the nut 58 has passed along the tap shank to a position adjacent the rear dies 50".

From their advanced position the spindles 17 and 18, and-the taps 21 and 22, are retracted by the continue rotation of cam cylinder 33, and the consequent actuation of the operating levers of the spindles.

As the operation of both the spindles, and their associated elements, is identical during advancing and retracting movement of the spindles; the description of their action during retraction. as during advancing movement, may be simplified by describing mereiy the action of one spindle 18 and its associated elements.

During retracting movement of the spindle 18 from the fully advanced position shown in Figure 4, tap 22 carries with it the blank 60 which it has already engaged. This blank is prevented from rotating with the tapby its engagement with the squared extension or way 61 of nut feeding matrix 62 in which the blank is slidable.

As the spindle is retracted, the rearward dies 50 are allowed to open, because of the contact of their beveled faces 50 with the chamfered face 57 of annular member 57*.

' In this position the inclination of the spindle lever.

permits the nuts to pass by gravity between dies 50* into the hollow passage 63 within the spindle. In. figure 5 the nut 58 is shown as having passed from the tap shank, the nut 59 is sliding along the shank. and the blank (30 has passed off the threaded portion of the tap.

is the dies 50 open to permit passage of nuts therehetween, the dies 50 close to engage the squared portion 22 on the shank of the tap. The tap is thus held at all times by at least one or the other of the two sets of dies, and in the central position of its travei the tap is held by both sets of dies.

During the next advance of the spindle, the tap 22 first finishes tapping the blank 60, which it has already engaged, then the tap engages the next succeeding blank as it reaches its most forward position. Each operating cycle thus results in the tapping of one nut.

Safety means are provided to prevent ine'ury to the mechanism if a nut blank should oecome caught or jammed in the blank holding matrix 62, such means being shown in detail in Figures 6 and 7. As shown in such figures, the lever 37, operated by cam cylinder 33 is freely mounted on its shaft 39, but is normally held rigidly thereon by its engagement with collars 64 and 65. 0f these, the collar 64 is rigidly secured to shaft 39 by a set screw 66, while the collar 65 is slidably mounted on the shaft by means of a screw 67 extendng into a key wa 68. On the face of coilar 65 which is ad1acent the iever 37 there is a V-shaped ridge 69 which fits a t-shaped groove 70 in the base of the Collar 65 is normally maintained in engagement with lever 37 by a coiled spring which bears against collar 65 and against a lixed coiiar 72. Lever 37 is thus held to shaft 39 so that its oscillation produces osciliation of the shaft. and of the spindle actuating elements connected therewith.

The coiled spring 71, which maintains collar in engagement with lever 37, may be made relativeiy light because of the interlocking engagement of the V-shaped ridge and V-shaped groove. If there is any opposition to the oscillation of shaft 39, the oscillation of iever 37 forces the collar 65 rearwardly out of engagement with the lever. Lever 37 may then oscillate freely without producing forced oscillation of shaft 39.

Associated with each spindle is a nut feeding matrix 62, supported by a standard 73 on the bed plate 1. A hopper '74 supplies the nut blanks to the matrix. As the hopper 74 may be identical with the hopper shown and described in the patent to Hubert Crehan, No. 1,149,553, its structure will not be specifically described herein.

The nut blanks 60 are fed by gravity from the hopper 74, by way of chute 75, to the matrix 62. Light arched springs 90, are

mounted in recesses 91 in the inner wall of the matrix 62. These springs serve to retain and center the blank, and avoid any possibility of the entrance of the tap at an angle to the body of the blank. Slidably mounted in the squared passage 61 of matrix 62 is a feeding block 76, provided with a cavity 77 for receiving the end of the tap. This feeding block 76 is reciprocated to force a blank on to the tap.

The means for reciprocating the feeding block 76 comprise a rod 78 which has a threaded engagement with the rear of the feeding block, and which carries two collars or shoulders 79 and 79*. Between collars 79 and 79* is a forked lever 80, which has a fixed engagement on a shaft 81 housed in standards 82 and 83.

Shaft 81 is oscillated to produce forward movement of feeding block 76, in forcing blanks on the tap 22, by meansof' a lever 84, which is secured to the shaft and which carries a weight 85. In this arrangement forward movement of the feeding block is produced by a force equal only to the gravitational pull on the weight and the moment arms ofits levers. There is therefore, no undue thrust against the tap if a nut blank should be improperly presented in the passa e or chamber 61 of the matrix.

he feeding block 76 is positively retracted by connections to cross shaft 39. Connections for this purpose comprise an arm 86 secured to the shaft 81. Through the lower portion 86 of arm 86 slidably passes a rod 87, which is pivotally connected at 88 to an arm 88. This arm 88 is secured to thecross shaft 39, which is oscillated by the rotating cam cylinder 33. On the portion of rod 87 which extends beyond the portion 86 of arm 86 is a nut 89, which forms the only connection between the rod and arm. Rod 87 can thus slide in arm .86, during outward movement of the rod, without changing the position of the arm. Upon inward movement of the rod, however, the arm 86 is moved, against the resistance of counterweight to turn shaft 81 and retract feeding block 7 6.

It will be noted that feeding block 76 acts to controlthe passage of nut blanks into matrix 62. During the advancing movement of the feeding block, it closes communication between the chute 75 and the matrix, but its retraction again establishes such communication.

Advantages of the present invention reside in the structure of the spindles and tap holding chucks, which renders them simple and capable of the rapid tapping and discharge of nuts.

Other advantages reside in both the struc tures which avoid injury to the mechanism because of amming of the nuts or failure of the chucks to function properly. These permit the machine to be operated without skilled supervision, and thus result in a great saving in the time of highly paid operators.

The machine as a whole is so arranged as to tap and deliver an unusually great number of nuts within a given period of time.

What I claim is:

1. In an automatic. nut tapping machine the combination of a driving shaft, :1 cylindrical cam mounted to rotate with said shaft, a shaft oscillated by connection with said cam, a reciprocating spindle carrying a tap, means for presenting nut blanks to said spindle, connections from the oscillated shaft to said spindle for advancing and retracting the same, connections from said oscillated shaft to the blank presenting means for actuating such means, and a resiliently maintaine jointin said oscillated shaft arranged to yield when resistance to the oscillation of the shaft is encountered.

2. In an automatic nut tapping 'machine the combination of a reciprocating spindle, a chuck carried by the spindle, a tap having a shank extending into said chuck, stationary means arranged to cooperate with the chuck during advancement and retraction of the spindle to cause the chuck to engage different portions of the tap shank in different positions of the spindle and chuck a ram arranged to position a nut blank until the blank has been contacted by the spindle at the limit of its forward movement, an actuating shaft, independent connections from the actuating shalt to the spindle and to the ram for advancement and retracting the spindle and actuating the ram, means for oscillating the actuating shaft, and a resiliently maintained joint in the actuating shaft arranged to yield when resistance to the oscillation of the shaft is encountered.

3. In an automatic nut tapping machine the combination of a driving shaft, a cylindrical cam mounted to rotate with said shaft, a shaft oscillated by connections with said cam, a reciprocating spindle carrying a tap, means for presenting nut blanks to said spindle, connections from the oscillated shaft to said spindle for advancing and retracting the same, and connections from said oscillated shaft to the blank presenting means for resiliently actuating such means.

4. In an automatic nut tapping machine the combination of a driving shaft, a cylindrical cam mounted to rotate with said shaft, a shaft oscillated by connections with said cam, a reciprocating spindle carrying a tap, means for presenting nut blanks to said spindle, direct connections from said driving shaft to the reciprocating spindle for rotation of the same, connections from the oscillated shaft to said spindle for advancing and retractingihe same, and connections from said oscillated Shift to the blank presenting means for resiliently actuating such means.

5. In an automatic nut tapping machine the combination of a driving shaft 2. cylindrical cam mounted to rotate with said shaft, a shaft oscillated by connections with said cam, a reciprocating spindle carrying a tap, means for presenting nut blanks to said spindle, direct connections from said driving shaft to the reciprocating spindle for rotation of the same, connections from the oscillated shaft to said spindle for advancing and retracting the same, and connections from said oscillated shaft to the blank presenting means for resiliently feeding a nut blank toward the advancing spindle.

6. In an automatic nut tapping machine the combination of a main driving shaft, a cylindrical cam mounted to rotate therewith, an auxiliary shaft oscillated by a connecting link to said cam, a reciprocating spindle carrying a tap, resilient means for feeding nuts to said tap, and connections to said oscillating shaft for producing both reciprocation of the spindle and actuation of the nut feeding means.

7. In an automatic nut tapping machine the combination of a driving shaft, a cylindrical cam mounted to rotate therewith, an auxiliary shaft oscillated by connections to said cam, a reciprocating spindle carrying a tap, resilient means for feeding nuts to said tap, and connections to said oscillating shaft for producin reciprocation ofthe spindle and permitting operation of the nut feeding means for feeding nut blanks toward the tap in the spindle during advancement of said tap.

. p In witness whereof I hereunto set my hand.

WILLIAM A. CREHAH, 

